Yesterday, Elon Musk lost a rocket and $780 million

Thursday started badly for Elon Musk when one of his SpaceX Falcon 9 rockets exploded on the launchpad, days before it was set to take a payload into orbit. Things got worse when Mark Zuckerberg discovered his $95 million satellite was sitting on top of the rocket, and took to Facebook to express his “deep disappointment.”

But as it turns out, blowing up a multi-million-dollar rocket was not Elon’s most expensive mistake yesterday.

As Bloomberg reports, share movements and regulatory filings related to Tesla and SolarCity, two of Musk’s other companies, cost him $779 million yesterday. The stock in both those companies (which are set to merge) took a sharp drop yesterday, with Tesla down 4% and SolarCity dropping by 9%. According to Fortune, the drop was due to cash concerns in Tesla, and ongoing worries from investors over Tesla’s merger with SolarCity.